An atmospheric environmental problem has become more and more serious due to the pollution materials generated by the development of the industry. Atmospheric pollution causes many health problems including respiratory diseases in the human body, and also causes a lot of damage to plants and properties. Among the pollution materials, the most abundant atmospheric pollution material is dust. In order to efficiently control and operate the emission of dust, it is necessary to identify the characteristics of generated gas and dust and install appropriate dust collection facilities.
Currently, widely used dust collection technologies include scrubbing-type dust collection technology, electrostatic dust collection technology, and filter-type dust collection technology.
Scrubbing-type dust collection technology is a technology designed to collect dust particles in such a way as to generate liquid droplets by applying physical force to a spray liquid and to collide and contact the liquid droplets with dust-containing gas, and can also process harmful gas. Although in most cases, water is used as a cleaning liquid, toxic gas may be removed by reacting the toxic gas with a liquid obtained by adding chemical additives to a spray liquid. This scrubbing-type dust collection technology is problematic in that it is difficult to apply the scrubbing-type dust collection technology to the collection of dust contained in gas under high-temperature and high-pressure conditions and wastewater processing cost is rather high.
Electrostatic dust collecting technology is technology designed to charge particles, such as dust and mist, contained in discharge gas by means of corona discharge and to move the particles to the surface of a dust collection electrode plate and then collect the particles by means of an electric field. This electrostatic dust collecting technology is efficient to remove pollution materials in a place where a large amount of dust is discharged, such as a power plant, a cement sintering furnace, a glass melting furnace, and an incineration plant.
Filter-type dust collection technology is technology that exhibits the best dust collecting performance compared to other dust collection technologies, and recently it has been widely used in dust generation processes and combustion facilities. Although it is difficult to apply a filter dust collector under a condition in which the bad condition of exhaust gas is present and a large amount of moisture is contained, a filter appropriate for the conditions of gas to be processed and the characteristics of dust to be collected has been developed and used. In this filter-type dust collection technology, there is required the process of dedusting dust collected in a filter. For this purpose, it is necessary to perform dedusting by means of a timer, a solenoid valve, and a diaphragm valve.
Therefore, the proposed preceding Korean Patent No. 0828487 (May 2, 2008) is configured such that dust-containing air is introduced into a dust collection chamber via a transfer pipe and passed through a collision plate 1, dust is adhered to the surface of a filter 4, and filtered clean air is passed through a filter case 3 inside the filter 4 and discharged through an upper atmospheric dump valve 9, as shown in FIG. 1.
The dust adhered to the surface of the filter 4 is continuously and automatically cleaned by a diaphragm valve 5, i.e., pulse jet-type cleaning equipment, and dust 2 is collected in a lower hopper and discharged through a discharge device 10.
A cleaning device is installed below an air header 7 installed outside a dust collector, and instantaneously sprays high-pressure air (of 4 to 5 Kg/cm2) from the blow tube 8 (for 0.2 seconds) by the sequential operation of the diaphragm valve 5, so that secondary air that is 5 to 7 times the amount of sprayed air can be sucked from the surroundings and introduced into the filter 4. At the moment, the dust adhered to the filter 4 can be efficiently cleaned by means of the instantaneous vibration attributable to a pulsating shock and the air flowing back to the outside.
The diaphragm valve 5 performs the cleaning operation of the filter 4 in such a manner that, when a pulse operation signal is received by a solenoid valve 5-5 from a program logic controller (PLI), internal pressure is released via a vent 5-4, a rubber plate 5-2 is instantaneously moved backward and returned (moved forward), and thus high-pressure air is supplied to a blow tube 8 connected to an outlet side 5-7, as shown in FIG. 2. In this case, a low-tension spring 5-3 configured to withstand internal pressure and mediate impact upon the application of a pulse is installed behind the rubber plate 5-2.
Meanwhile, a detection device 11 for the erroneous operation of a diaphragm valve is installed in the vent 5-4 of the diaphragm valve 5. In other words, the detection device 11 for the erroneous operation of a diaphragm valve includes a body 11-4 configured such that a ball 11-3 adapted to is vertically moved by pressure discharged from the vent 5-4 of the diaphragm valve 5 is contained therein, a detection unit configured to detect a pulse operation signal according to the lifting of the ball 11-3 inside the body 11-4, and a countermeasure unit configured to detect the occurrence of the abnormality of the diaphragm valve 5 and transfer the information to an electronic valve.
Furthermore, the detection unit is connected via wire so that a signal can be transferred to an input/output terminal box 11-9 containing a timer upon the application of a pulse in a state in which a hollow cylindrical fastening flange 11-2 has been connected to the top of the body 11-4 and the top of the hollow cylindrical fastening flange 11-2 has been covered with a cap 11-1 containing a limit switch.
An electronic valve 11-6, i.e., a device configured to block discharge gas when the erroneous operation of the diaphragm valve 5 is detected, is installed on the side flange of the body 11-4, the operation wiring of the electronic valve 11-6 is connected to the input/output terminal box 11-9, a nipple 11-7 having threads on both sides thereof is fastened, and an elbow-type pressure vent 11-8 is connected, thereby completing the countermeasure unit.
However, since the above-described conventional technology includes the detection unit configured to detect a pulse operation signal in response to an increase in pressure released from the vent 5-4 of the diaphragm valve 5 and the countermeasure unit configured to detect the occurrence of the abnormality of the diaphragm valve 5 and transfer the information to the electronic valve 11-6, it can prevent differential pressure inside a dust collection chamber from increasing upon the erroneous operation of the diaphragm valve 5 and can rapidly take a countermeasure upon the occurrence of an abnormality. However, this configuration is problematic in that there occurs an accident in which the operation of the operating dust collector must be abruptly shut down because the diaphragm valve 5 cannot be operated when any one of the input/output terminal box 11-9 containing a timer, the electronic valve 11-6, and the solenoid valve 5-5 fails in a state in which the diaphragm valve 5 is not normally operated. When an emergency shutdown is not performed, the filter 4 reaches a limit differential pressure, so that problems arise in that lifespan is shortened and in that dust is discharged to the air when the filter 4 is damaged and, thus, atmospheric environmental pollution is caused.